Another reason is that the runner-ups simply decided that they weren't up to par in that field (they did lose, after all), but also discovered they had talent in a different field during their time on the show (acting is the most common such talents) and successfully pursued a career in that without attaining the trappings of the original competition's winner.

Their free hour-long test is fascinating to help you determine compatibility markers, however, there's zero way to tell if the person you're matched with also has an account, and therefore can reply to your questions.